Detecting drug-impaired drivers has gained a high level of importance during the last decade. In most cases, the reason to identify drug-impaired individuals participating in public traffic is motivated by safety issues and legal implications caused by these individuals operating cars, machinery or other equipment. Safety and legal issues are both very important in the context of a mobile society heavily relying on motorized vehicles for transportation. Financial implications for individuals or groups of the society resulting from accidents are considerable. Recognizing the importance of these facts, the abatement of drug-related accidents has been identified as prime target by the U.S. government.
Conventional technology utilized for drug detection in general relies on a variety of different analytical methods, e.g., GC, HPLC, MS, GC-MS, etc. Most commonly, chemical or physico-chemical methods are employed to analyze the drug composition and the drug contents of urine or blood samples. However, these approaches are time-consuming, require expensive equipment and well trained operators, and may necessitate medical supervision.
The detection of drug vapors or vapors resulting from metabolization of drugs in the human body in traffic and traffic-related situations, although of great importance, is a much less explored field. Almost all known methodologies are limited to laboratory applications, due to the fact that test procedures are time consuming and complicated; stationary equipment is required to conduct the tests. Only recently, a sampling method for cocaine vapor in cargo containers has been used by the Canadian Customs; see, Detection of Drugs in Cargo Containers by High Volume Air Sampling, P. Neudorfl, et al., SPIE Conference, Boston, Mass. (November 1996).
Most conventional analytical methods used for drug detection are based on technologies which can only be applied external to a vehicle and require the cooperation of tested individuals, with authorities conducting the drug test. None of them is suitable for providing real-time information about the presence of drugs in the field. In addition to this, most conventional methods share several significant shortcomings:
(a) Only selected vehicles or individuals can be tested for drugs, due to logistical and personnel limitations, leading to a high percent rate of undetected drugs. PA1 (b) Vehicles with drivers suspected of being under the influence of drugs have to be stopped, necessitating costly checkpoints and follow-up examinations. PA1 (c) Expensive equipment has to be set up and maintained at high cost. PA1 (d) Human interaction is required, accounting for a variety of different problems, e.g., high personnel costs, risk of violent encounters, etc. PA1 (e) Testing is sporadic and does not provide continuous monitoring of traffic and vehicles. PA1 (a) a laser comprising a gain medium having two opposed facets within a laser resonator and functioning as an intracavity spectroscopic device having a first end and a second end, the first end operatively associated with a partially reflecting (i.e., partially transmitting) surface; PA1 (b) a reflective or dispersive optical element (e.g., a mirror or a diffraction grating) operatively associated with the second end to define a broadband wave-length laser resonator between the optical element and the first end and to thereby define an external cavity region between at least one facet of the gain medium and either the first end or the second end or both ends; PA1 (c) the external cavity region being exposed to a sample of air representative of the air in the cabin of the vehicle to enable any molecules associated with drugs or metabolized by-products of drugs to enter thereinto; PA1 (d) a detector spaced from the first end and providing an output detector signal; PA1 (e) appropriate electronics for measuring and analyzing the detector signal; PA1 (f) a housing for containing at least the laser, the partially reflecting surface, and the optical element, the housing being configured to prevent escape of stray radiation into the cabin and to permit air from the cabin to continuously circulate through the external cavity region for analysis; and PA1 (g) means for driving the laser (e.g., electrical or optical). PA1 (1) sensing any drug-related vapors in the vehicle by the on-board sensor; and PA1 (2) providing a signal indicative of presence of any drug-related vapors.
These facts lead to the conclusion, that (i) conventional technologies available to identify drugs in traffic-related situations are limited in their applicability and (ii) due to their conceptual shortcomings, these methods are even less suited to contribute to a significant further reduction of drug related situations in traffic as required by the government.
The above-identified patent application Ser. No. 09/131,437 discloses and claims small, highly-sensitive, on-board alcohol detectors. The on-board alcohol detector is mounted within the cabin area of vehicles. However, the prior art for detectors useful for detecting drugs, or the metabolized by-products of drug ingestion, is even less well-developed than the prior art for alcohol detectors. Accordingly, there is a need for a new generation of small, highly-sensitive, on-board detectors which would help to greatly reduce the number of drug-impaired drivers by preventing individuals under the influence from driving vehicles. These sensors, mounted within the cabin area of vehicles, would address the problem of driving under the influence before it even arises. These small and highly sensitive drug detectors could also be used to detect drugs or by-products of drugs in other enclosed spaces.